Article
Chemistry, Physical
Teng-Jan Chang, Yu-Sen Jiang, Sheng-Han Yi, Chun-Yi Chou, Chin- Wang, Hsin-Chih Lin, Miin-Jang Chen
Summary: This paper introduces an atomic layer annealing (ALA) technique to achieve ferroelectricity in sub-10 nm HZO thin films with low thermal budget. The ALA treatment on each HfO2 monolayer is found to be superior in terms of crystallinity and ferroelectric properties compared to the treatment on each ZrO2 monolayer. The study demonstrates the effectiveness of ALA in atomic tailoring of nanoscale thin films at low temperature.
APPLIED SURFACE SCIENCE
(2022)
Article
Physics, Applied
Yong Chan Jung, Jin-Hyun Kim, Heber Hernandez-Arriaga, Jaidah Mohan, Su Min Hwang, Dan N. Le, Akshay Sahota, Harrison Sejoon Kim, Kihyun Kim, Rino Choi, Chang-Yong Nam, Daniel Alvarez, Jeffrey Spiegelman, Si Joon Kim, Jiyoung Kim
Summary: This study investigates the robust ferroelectric properties of low-temperature (350 ?) Hf0.5Zr0.5O2 (HZO) films. It is found that the use of anhydrous H2O2 oxidant enables the HZO films to fully crystallize at a lower temperature, with fewer defects. Additionally, this low-temperature crystallization process improves device reliability by suppressing electrode oxidation.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Physical
Mirine Leem, Deokjoon Eom, Heesoo Lee, Kwangwuk Park, Kwangsik Jeong, Hyoungsub Kim
Summary: In this study, HZO films were grown directly on single-crystalline MoS2 flakes using ALD with H2O or O3 oxidants. The O3-based ALD process oxidizes the MoS2 surface at the atomic layer level and facilitates the conformal deposition of an HZO film without surface treatment of MoS2. Annealing the O3-based HZO film significantly improves the ferroelectric properties, but also leads to diffusion of S, Hf, Zr, and O towards the Mo layer, reducing the weak HZO bonds.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Dong Hyun Lee, Geun Taek Yu, Ju Yong Park, Se Hyun Kim, Kun Yang, Geun Hyeong Park, Jin Ju Ryu, Je In Lee, Gun Hwan Kim, Min Hyuk Park
Summary: This study investigated the impact of deposition temperature and impurity concentration on the physical/electrical properties and polarization switching kinetics of atomic-layer deposited Hf0.5Zr0.5O2 thin films. It was found that decreasing deposition temperature led to increased residual impurity concentration, resulting in smaller grain size and shorter polarization switching time. The lower energy barrier for nucleation of oppositely polarized domains and increased spatial inhomogeneities were attributed to this phenomenon.
Article
Chemistry, Physical
Chin- Wang, Chun-Yuan Wang, Teng-Jan Chang, Yu-Sen Jiang, Jing-Jong Shyue, Hsin-Chih Lin, Miin-Jang Chen
Summary: This paper reports significant ferroelectricity in 6 nm HZO thin films achieved by TiN capping electrode prepared by atomic layer deposition (ALD). The mechanisms of the TiN capping effect on the distinct ferroelectric properties are investigated, showing promising potential for next-generation ferroelectric applications.
APPLIED SURFACE SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Jae Hur, Panni Wang, Nujhat Tasneem, Zheng Wang, Asif Islam Khan, Shimeng Yu
Summary: The doped/alloyed HfO2 and ZrO2 thin films have brought revolution to both the field of ferroelectric physics and various device applications, especially when combined in a 1:1 ratio for distinctive ferroelectric polarization. Through controlling process conditions and additional Ar plasma treatment, researchers are able to manipulate the ferroelectric and antiferroelectric phases of HZO films.
JOURNAL OF MATERIALS RESEARCH
(2021)
Article
Nanoscience & Nanotechnology
Aniruddh Shekhawat, H. Alex Hsain, Younghwan Lee, Jacob L. Jones, Saeed Moghaddam
Summary: This study investigates the effects of ferroelectric and interface film thickness on the tunneling electroresistance or ON/OFF current ratio of Hf0.5Zr0.5O2/Al2O3 based FTJ devices. By optimizing the thickness of the ferroelectric and interface films, it is possible to enhance the ON/OFF current ratio, while analyzing the relationship between interface properties improves the performance of the FTJ.
Article
Chemistry, Multidisciplinary
Anastasia Chouprik, Vitalii Mikheev, Evgeny Korostylev, Maxim Kozodaev, Sergey Zarubin, Denis Vinnik, Svetlana Gudkova, Dmitrii Negrov
Summary: This study elucidates an approach to suppress the wake-up effect in ultrathin Hf0.5Zr0.5O2 films and reveals the important role of built-in fields in the ferroelectricity and stability of thin films.
Article
Physics, Applied
Deokjoon Eom, Jehoon Lee, Woohui Lee, Joohee Oh, Changyu Park, Jinyong Kim, Hyangsook Lee, Eunha Lee, Hyoungsub Kim
Summary: The influence of atomic-layer-deposition (ALD) temperature and metal electrodes on the ferroelectric properties of Hf0.5Zr0.5O2 films was investigated. The ALD temperature affected the phase transition temperature, while the metal electrode influenced the orientation and maximum remanent polarization of the orthorhombic grains. The electrode characteristics also affected the fatigue and wake-up characteristics of the films.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Chun-Yi Chou, Hsing-Yang Chen, Yu-Sen Jiang, Hsin-Chih Lin, Miin-Jang Chen
Summary: The study proposes a novel atomic layer substrate bias induced crystallization technique for the preparation of high-performance HfO2-based H0.5Zr0.5O2 thin films. The technique enables crystallization and densification of the films, leading to enhanced ferroelectric polarization and dielectric constant. It also suppresses the formation of oxygen vacancies, extending the endurance and enabling wake-up free operation of the thin films. The exceptional ferroelectric properties make these films highly favorable for non-volatile ferroelectric memory devices in the future.
Article
Materials Science, Multidisciplinary
Ting-Yun Wang, Chi-Lin Mo, Chun-Yi Chou, Chun-Ho Chuang, Miin-Jang Chen
Summary: In this paper, the concept and method of monolayer engineering by atomic layer deposition (ALD) were proposed and implemented to improve the crystallinity and ferroelectricity of Hf0.5Zr0.5O2 (HZO) thin films. By substituting one ZrO2 for one HfO2 atomic layer, a high ferroelectric remnant polarization (P-r) of 15 mu C/cm(2) was achieved in the HZO thin film with a thickness of only 4 nm at a low annealing temperature of 370 degrees C. This study demonstrates that monolayer engineering by ALD enables atomic tailoring to enhance the material and physical properties of nanoscale thin films.
Article
Nanoscience & Nanotechnology
Hae Won Cho, Pavan Pujar, Minsu Choi, Seunghun Kang, Seongin Hong, Junwoo Park, Seungho Baek, Yunseok Kim, Jaichan Lee, Sunkook Kim
Summary: The direct growth of polar orthorhombic phase in Hf0.5Zr0.5O2 (HZO) thin films using Pulsed Laser Deposition (PLD) has been reported. The PLD-HZO technique, integrated with HfO2 dielectric, has shown promising results for low power integrated digital/analog circuits.
NPJ 2D MATERIALS AND APPLICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Jeong Min Hwang, Seung-Min Han, Hanuel Yang, Seungmin Yeo, Seung-Hun Lee, Chan Woo Park, Gun Hwan Kim, Bo Keun Park, Younghun Byun, Taeyong Eom, Taek-Mo Chung
Summary: Ru thin films were grown via ALD using a novel Ru precursor, resulting in metallic films with low resistivity at deposition temperatures between 200 and 300 degrees C. Self-limiting growth was achieved by varying the precursor and O-2 feeding times, leading to shorter incubation times compared to traditional Ru ALD methods.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Teng-Jan Chang, Hsing-Yang Chen, Chin- Wang, Hsin-Chih Lin, Chen-Feng Hsu, Jer-Fu Wang, Chih-Hung Nien, Chih-Sheng Chang, Iuliana P. Radu, Miin-Jang Chen
Summary: In recent years, the interest in Hf0.5Zr0.5O2 (HZO) thin films has grown due to their well-behaved ferroelectricity and high compatibility with semiconductor integrated circuit technology. The phase transformation and wake-up effect in HZO were identified using the precession electron diffraction (PED) phase mapping technique. The absence of the tetragonal (t-) phase is responsible for the wake-up-free property in the ferroelectric HZO thin film. The wake-up-free and pronounced ferroelectricity of the nanoscale HZO thin film in this study may have practical implications for various ferroelectric applications.
Article
Materials Science, Multidisciplinary
Liying Wu, Minni Qu, Xiulan Cheng
Summary: This paper investigates the ferroelectric properties of 20-nm-thick Hf0.5Zr0.5O2 films deposited using atomic layer deposition with O-3 or H2O as oxygen sources. The results show that the use of O-3 as an oxygen source is more suitable for the fabrication of ferroelectric Hf0.5Zr0.5O2 films for next generation memory applications.
Review
Chemistry, Multidisciplinary
Ju Yong Park, Duk-Hyun Choe, Dong Hyun Lee, Geun Taek Yu, Kun Yang, Se Hyun Kim, Geun Hyeong Park, Seung-Geol Nam, Hyun Jae Lee, Sanghyun Jo, Bong Jin Kuh, Daewon Ha, Yongsung Kim, Jinseong Heo, Min Hyuk Park
Summary: The research on ferroelectric memories has been limited in the past due to scalability and compatibility issues. However, the discovery of ferroelectricity in certain oxides has revived interest in the field. The potential of inducing nanoscale nonvolatility in gate insulators has been demonstrated. However, technical limitations and variations in reliability need to be addressed for practical applications in various types of devices.
ADVANCED MATERIALS
(2023)
Review
Chemistry, Multidisciplinary
Thomas Mikolajick, Min Hyuk Park, Laura Begon-Lours, Stefan Slesazeck
Summary: Due to the low voltage driven switching and nonvolatility, ferroelectric materials have great potential for low power nonvolatile electronic devices. However, the incompatibility of well-known ferroelectrics with existing semiconductor technology has hindered the competitiveness of these devices. The discovery of ferroelectricity in hafnium oxide has changed this situation. This article summarizes the material science of ferroelectricity in hafnium oxide, discusses the status of nonvolatile ferroelectric memories, explores applications like in-memory computing, and showcases the realization of neuromorphic computing systems using basic building blocks of spiking neural networks.
ADVANCED MATERIALS
(2023)
Correction
Materials Science, Multidisciplinary
Dong Hyun Lee, Geun Taek Yu, Ju Yong Park, Se Hyun Kim, Kun Yang, Geun Hyeong Park, Jin Ju Ryu, Je In Lee, Gun Hwan Kim, Min Hyuk Park
Review
Chemistry, Multidisciplinary
Dong Hyun Lee, Younghwan Lee, Yong Hyeon Cho, Hyojun Choi, Se Hyun Kim, Min Hyuk Park
Summary: Ferroelectric materials are regarded as ideal for emerging memory devices due to their unique remanent polarization. However, the slow progress of ferroelectric memories is attributed to issues like the lack of CMOS-compatible and scalable materials. In recent years, the discovery of ferroelectricity in CMOS-compatible materials like (Hf,Zr)O-2 and (Al,Sc)N has sparked increasing interest. With advancements in material fabrication, a metastable polar phase and switchable polarization can be induced in these materials. However, challenges still exist for their use in emerging memory devices, which are comprehensively reviewed in this article.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Atif Jan, Thomas Rembert, Sunil Taper, Joanna Symonowicz, Nives Strkalj, Taehwan Moon, Yun Seong Lee, Hagyoul Bae, Hyun Jae Lee, Duk-Hyun Choe, Jinseong Heo, Judith MacManus-Driscoll, Bartomeu Monserrat, Giuliana Di Martino
Summary: Ferroelectric materials provide a low-energy, high-speed alternative for conventional logic and memory circuitry. By using plasmon-enhanced spectroscopy, the real-time tracking of oxygen vacancy migration in 5 nm hafnium zirconium oxide during the pre-wake-up stage is achieved, revealing the structural phase change and its effects on device wake-up and fatigue. These findings are supported by Raman, photoluminescence, and darkfield spectroscopy, along with density functional theory and finite-difference time-domain simulations.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Engineering, Electrical & Electronic
Dong Hee Han, Ae Jin Lee, Min Kyeong Nam, Seungwoo Lee, Su Jin Choi, Youngjin Kim, Taehwan Moon, Woojin Jeon
Summary: The ferroelectric properties of Hf0.5Zr0.5O2(HZO) were investigated based on the preferred orientations of the titanium nitride (TiN) bottom electrode (BE). (111) and (200)-oriented TiN were used as BEs. The difference in crystallinity of HZO was observed and its electrical properties were compared. Through various crystal structure analyses and electrical measurements, it was found that the HZO thin film grown on TiN(200) had more ferroelectric non-centrosymmetric orthorhombic phase in the pristine state due to the local epitaxial relation between TiN(200) and HZO.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Younghwan Lee, Hyun Woo Jeong, Se Hyun Kim, Kun Yang, Min Hyuk Park
Summary: This article discusses the effects of stress/strain on FF thin films, including the mechanisms, material properties, and device performances. Research in this field is crucial for understanding and optimizing FF thin films and related devices.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Sanghyun Jo, Hyangsook Lee, Duk-Hyun Choe, Jung-Hwa Kim, Yun Seong Lee, Owoong Kwon, Seunggeol Nam, Yoonsang Park, Kihong Kim, Byeong Gyu Chae, Sangwook Kim, Seunghun Kang, Taehwan Moon, Hagyoul Bae, Jung Yeon Won, Dong-Jin Yun, Myoungho Jeong, Hyun Hwi Lee, Yeonchoo Cho, Kwang-Hee Lee, Hyun Jae Lee, Sangjun Lee, Kab-Jin Nam, Dongjin Jung, Bong Jin Kuh, Daewon Ha, Yongsung Kim, Seongjun Park, Yunseok Kim, Eunha Lee, Jinseong Heo
Summary: Ferroelectric zirconium-doped hafnia (Hf0.5Zr0.5O2) can be used to create negative differential capacitance behavior in capacitors and transistor gate stacks, providing reliable enhancements in switching performance. The effect is achieved in metal-oxide-semiconductor capacitors and field-effect transistors, leading to improved device performance with increased on current and decreased off current.
NATURE ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Song-Hyeon Kuk, Seung-Min Han, Bong Ho Kim, Joon Pyo Kim, Seong-Kwang Kim, Seung-Yeop Ahn, Min Hyuk Park, Jae-Hoon Han, Sang-Hyeon Kim
Summary: HfZrOx-based Si n-/p-type ferroelectric field-effect transistors (n/pFEFETs) were studied from 300 to 82 K using pulse measurements, revealing the device physics at low temperatures. FEFET showed significantly improved performance at 82 K, including a read-after-write latency of <100 ns and write endurance exceeding 10^10 cycles without device degradation. Despite the increase in coercive field, a lower write voltage was achievable at 82 K compared to 300 K. This enhancement is attributed to frozen trap sites and increased coercive field at 82 K. Our work provides a comprehensive understanding of device physics and highlights the potential of FEFET as a cold memory.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Kun Yang, Gi-Yeop Kim, Jin Joo Ryu, Dong Hyun Lee, Ju Yong Park, Se Hyun Kim, Geun Hyeong Park, Geun Taek Yu, Gun Hwan Kim, Si Young Choi, Min Hyuk Park
Summary: The ferroelectricity of Hf0.5Zr0.5O2 thin films makes them suitable for current and future electronic devices. A new strategy of providing oxygen from a surface-oxidized W electrode is proposed to maximize the remanent polarization of Hf0.5Zr0.5O2. Comparisons between Hf0.5Zr0.5O2 thin films with TiN and W electrodes reveal that the oxygen supply from the W electrode enhances the ferroelectric properties and increases the remanent polarization.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Taehwan Moon, Hyun Jae Lee, Seunggeol Nam, Hagyoul Bae, Duk-Hyun Choe, Sanghyun Jo, Yun Seong Lee, Yoonsang Park, J. Joshua Yang, Jinseong Heo
Summary: We propose a new synaptic design for more efficient neuromorphic edge-computing, improving linearity and reducing variability. By using a parallel arrangement of ferroelectric tunnel junctions (FTJ) and an incremental pulsing scheme, we achieve better linearity for synaptic weight updating. Through experiments, we demonstrate the feasibility of this design with FTJ building blocks, showing the lowest reported variability of 0.036 for cycle to cycle and 0.032 for device among six dies across an 8 inch wafer. We further show improved synaptic performance and pattern recognition accuracy through experiments combined with simulations.
NEUROMORPHIC COMPUTING AND ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Geun Hyeong Park, Dong Hyun Lee, Hyojun Choi, Taegyu Kwon, Yong Hyeon Cho, Se Hyun Kim, Min Hyuk Park
Summary: This paper comprehensively reviews the emerging antiferroelectricity of fluorite-structured oxides and discusses their potential applications in semiconductor devices.
ACS APPLIED ELECTRONIC MATERIALS
(2023)
Correction
Chemistry, Multidisciplinary
Se Hyun Kim, Geun Taek Yu, Geun Hyeong Park, Dong Hyun Lee, Ju Yong Park, Kun Yang, Eun Been Lee, Je In Lee, Min Hyuk Park
CHEMICAL COMMUNICATIONS
(2023)
Review
Nanoscience & Nanotechnology
Sanghyeon Choi, Taehwan Moon, Gunuk Wang, J. Joshua Yang
Summary: This article reviews filament-free switching memristors and their potential in computing applications. Unlike filamentary memristors, filament-free switching memristors exhibit better uniformity and dynamic properties, enabling various new computing paradigms.
Review
Nanoscience & Nanotechnology
Jaewook Lee, Kun Yang, Ju Young Kwon, Ji Eun Kim, Dong In Han, Dong Hyun Lee, Jung Ho Yoon, Min Hyuk Park
Summary: HfO2 is a promising material for emerging ferroelectric and resistive switching memory devices due to its excellent electrical properties and compatibility with existing fabrication processes. The presence of oxygen vacancies (Vo) in HfO2 films greatly affects the material properties, device performance, and reliability. Understanding the formation mechanism and effects of Vo is crucial for improving the performance and reliability of HfO2-based devices.
